The application of heating rate to studies of polysiloxanes with cyanoethyl substituents and silazane polymers

详细信息    查看全文

• 作者：Zhu ; Qingzeng ; Guan ; Ruifang ; Meng ; Fanjun ; Feng ; Shengyu
• 关键词：Polysiloxanes ; Silazane polymers ; Heating rate ; DSC ; TGA
• 刊名：Thermochimica Acta
• 出版年：2003
• 出版时间：June 3, 2003
• 年：2003
• 卷：402
• 期：1-2
• 页码：193-197
• 全文大小：141 K

文摘

Thermal behaviour of polysiloxanes containing cyanoethyl side groups was studied by differential scanning calorimetry (DSC). Samples were quenched to −165°C and then reheated at different heating rates. The glass transition, an exothermal crystalline formation (cold crystallization) and endothermal melting of crystalline formations were detected. A broad cold crystallization peak and a melting peak were observed at a heating rate of 20K/min. However, the samples gave a sharp cold crystallization peak and three endothermal peaks using a heating rate of 5K/min. The DSC traces obtained were thus sensitive to heating rates. Thermal degradation of silazane polymers was studied by a thermogravimetric method. Three stages of degradation occur in the course of thermal decomposition. It was shown that the yields of pyrolytic product increased with the heating rate decreasing.